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Question about 1981 BMW (Rennsport?)

cyberdoggie

New member
Am looking to buy a bike from a gent who has has this 81 RS for the past 12 years. When he bought it he was told it was an Australian version of the bike that was a Rennsport edition that was upgraded from 70(71?) to 77hp. Is this true?

It looks like a beautiful bike. Seems that coloring is similar to the 1978 Motorsport coloring but with the stripe down the trunk and back of the bike too.

Have not purchased bike yet but very interested and would like to hear what others think.

Mark
 

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BMW never offered such a model. Very nice custom repaint. Does it have the double cross over header pipes?
 
Never have seen that paint scheme from the factory. Very nice looking custom and should be a joy to ride. RE: engine build. Unless the owner can show some form of documentation, the only way to prove comp ratio is via teardown and measurements of the top end.

Watch the MPG's. The 9.5cr engines tend to get considerably better mileage. 45+ mpg is typical. The lower comp 100's tend to see 40mpg or less. In both cases that assumes spec timing, balance and tune.

Two more things say custom paintwork. Mirror backs are painted white, never seen anything but black on the RS/RT. And I don't recall any factory pinstrips on the side covers on any factory paint code. It's a very tasteful custom.

Will say as well, the extra tubes for the US EPA version are on there. Did Australia import US spec machines???
 
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It has the larger mirrors from a later model bike. The 81 mirrors were smaller in size.The 81's were the last year for factory 40 mm. carbs. still a really nice bike!!Please tell us more about it.

All of this is not accurate, as those are original configuration mirrors and 40mm carbs lasted through 1984.

This is a USA model for sure, as it has the air injestion system pipes visible.
 
Another thought. Won't the VIN give you a little more detailed info about its origin?

I certainly do not possess the knowledge of others here, but when I saw that, my first thoughts were, "Huh. Looks good, but doesn't look like an original RS that I've seen of that vintage."

Bottom line is that it may be a very good motorcycle, but don't base your decision to purchase on a pedigree that may be a little sketchy. Base your decision on the fact that you'd be getting a great looking '81 RS.
 
BMW never offered such a model. Very nice custom repaint. Does it have the double cross over header pipes?

BMW Australia offered a number of "factory specials" over the years. I do not recall any being truly special, but may well be wrong. From memory they were typically different paint jobs and maybe a raid on the assessories options to spice things up. BMW themselves are well known for offering "specials" as a way to keep volumes up at the end of a product life cycle.

BMW Australia did indeed offer a Rennsport. Checking the VIN should point you in the right direction to determine the bike's originally intened destination. Checking contemporary sales materials from Australia will help determine the original specification. Regardless, it is a very sharp looking bike.
 
Thanks!

Owner is out of town until Nov 5 but I will get a VIN from him then. All excellent comments and yes the bottom line is that it seems to be down to a matter of personal taste for the custom paint, since it doesn't seem likely to be a factory issued paint job... (An re HP difference, given my leisurely riding habits that's not a factor for me anyhow.) Will post more when I learn the VIN.

Bike comes with the solo seat as well and black side bags. Orig owner had had for 14 years and has put maybe 10K on the bike. Bought with 40K on the bike. Owner was meticulous but didn't seem to change it at all, preferring to enjoy as is. (a feature in my book!)

Posting another pic...
 

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BMW Australia offered a number of "factory specials" over the years. I do not recall any being truly special, but may well be wrong. From memory they were typically different paint jobs and maybe a raid on the assessories options to spice things up. BMW themselves are well known for offering "specials" as a way to keep volumes up at the end of a product life cycle.

BMW Australia did indeed offer a Rennsport. Checking the VIN should point you in the right direction to determine the bike's originally intened destination. Checking contemporary sales materials from Australia will help determine the original specification. Regardless, it is a very sharp looking bike.

...and the Canadians had various polished parts and different colors than we saw in the US, but everything shows up on the VIN micro fishe and I have never seen big differences in the bikes or parts going to Australia.
 
front faring?

Al looking at the photo of the front. I thought the later RS bikes has a closed off front faring once there was an oil cooler as standard equipment. This seems to be vented. Is that normal?
 
According to Ian Falloon's book, the '77 and '78 models had the grilled front lower fairing peice, but beginning with the '79s, the piece was solid except for small vents around the lower sides as well as the opening up high for the oil cooler. If the VIN matches the 1981 model as an R100RS, then most likely someone swapped out the closed piece with the grilled one.
 
BMW Australia offered a number of "factory specials" over the years. I do not recall any being truly special, but may well be wrong. From memory they were typically different paint jobs and maybe a raid on the assessories options to spice things up. BMW themselves are well known for offering "specials" as a way to keep volumes up at the end of a product life cycle.

The only I've run across on this was on Phil Hawksley's site regarding the R100RT mono bikes. It was a bike designated as the R100LT. I find the following note on this page:

http://www.bmbikes.co.uk/photopages/photosr100rtmono.htm

"BMW R100LT. Such a model appears nowhere within BMW's own reference material however it has become clear that such a model designation was used within Australia and some reference has been found in French brochures. The designation appears to have been used at some point between 1993 and 1995 for what would appear to be the model that was designated R100RT Classic elsewhere in the world i.e. a mono-shock R100RT with many extras included as standard. I have no idea of the number of machine produced with this designation but I do have two chassis numbers from Australia 6339681 & 6338864 - the BMW ETK lists both of these numbers as R100RT. Exactly what extras were included is debatable although one guy claims it was fitted with a Corbin seat (I'd suspect this was more likely to have been the standard 'Comfort seat' which is a similar shape)."
 
According to Ian Falloon's book, the '77 and '78 models had the grilled front lower fairing peice, but beginning with the '79s, the piece was solid except for small vents around the lower sides as well as the opening up high for the oil cooler. If the VIN matches the 1981 model as an R100RS, then most likely someone swapped out the closed piece with the grilled one.

Just a note, my 79RS has the fully slotted grill as original. Build date 02/79
 
The only I've run across on this was on Phil Hawksley's site regarding the R100RT mono bikes. It was a bike designated as the R100LT. I find the following note on this page:

http://www.bmbikes.co.uk/photopages/photosr100rtmono.htm

"BMW R100LT. Such a model appears nowhere within BMW's own reference material however it has become clear that such a model designation was used within Australia and some reference has been found in French brochures. The designation appears to have been used at some point between 1993 and 1995 for what would appear to be the model that was designated R100RT Classic elsewhere in the world i.e. a mono-shock R100RT with many extras included as standard. I have no idea of the number of machine produced with this designation but I do have two chassis numbers from Australia 6339681 & 6338864 - the BMW ETK lists both of these numbers as R100RT. Exactly what extras were included is debatable although one guy claims it was fitted with a Corbin seat (I'd suspect this was more likely to have been the standard 'Comfort seat' which is a similar shape)."

The R100LT was sold in the US. This is my 1995 (now sold) R100LT that I bought when it had only 3K miles on it in Lubbock Texas. The LT was a standard RT with extras, such as 4-way flashers, radio with tape deck, trunk, copy of a Corbin seat, heated grips, and crash bars. I bought it from the the same dealer that sold it new. Not shown on the bike is the trunk, but I had it with the bike.

The seat was a poor copy of the Corbin and I replaced it later with a proper one. I kept the bike until a few years ago when I sold it during one of my dizzy spells to a guy in Florida. That bike took us all over West Texas, New Mexico, and Pennsylvania after a move there, and Missouri and Illinois after a move here.
 

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Related question re white BMW

Still waiting for the VIN. Going to see it on the 11th.

Has anyone ever seen the krausers that were made for the 78 Motorsport for sThis bike comes with Black bags but to complete the look - in my opinion - the white bags would be stunning. Are they just black bags resprayed white or made white through and through?
 
white through and through....

I have never cared much for the white bags, but on this bike... c'est magnifique!

78Motorsport.jpg
 
Still waiting for the VIN. Going to see it on the 11th.

Has anyone ever seen the krausers that were made for the 78 Motorsport for sThis bike comes with Black bags but to complete the look - in my opinion - the white bags would be stunning. Are they just black bags resprayed white or made white through and through?

There were simply white and black bags available. Nothing specifically made for the Motorsport. They are white plastic, not painted.

lm4.jpg
 
As reference my 81 rt had the oil cooler with the enclosed fairing front grill, I put the shark grill on it and removed the oil cooler.

Lots of people blamed the more enclosed grill for diode board failures, but the problem was poorly made diode boards.

In addition, while the Nikasil cylinders were fabulous and light years better than the earlier iron cylinders, they did dump lots of heat to the rider. Many "shade tree engineers" felt adding the bar-type grill would address the heat problem. If it did it was hardly measurable. One sees lots of these bikes running no lowers at all for the same reason.
 
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